YIELD, QUALITY AND PLANT NUTRIENT CONTENTS OF LETTUCE UNDER DIFFERENT DEFICIT IRRIGATION CONDITIONS

This research was carried out in two separate periods (spring and autumn) in 2018 to reveal the lettuce response of yield, some quality, and plant nutrient content under different water stress conditions. In the study, the effects of different irrigation levels applied with traditional deficit irrigation (TI) and partial rootzone drying (PRD) techniques on lettuce growing were investigated. Lettuce (Lactuca sativa var. crispa cv. 'Campania') was used as plant material. There were traditional farmers' method of irrigation (TF), 125% traditional irrigation (TI-125), 100% traditional irrigation (TI-100), 75% traditional irrigation (TI-75), 50% traditional irrigation (TI-50), 125% partial root-zone drying technique (PRD-125), 100% partial root-zone drying technique (PRD-100), 75% partial root-zone drying technique (PRD-75), 50% partial root-zone drying (PRD-50) technique treatments. According to the results of the research, it was determined that different water stress applications were effective on the criteria examined in lettuce. The highest total and marketable yield values were obtained from the TF application, the second-highest values from the TI-125 application, and the lowest yield from the PRD-50 in the autumn period. In the spring season, the lowest yield was obtained from TI-50 and PRD-50 applications. Based on the treatments, the yield values were decreased and changes were experienced with the increase of the water stress in other examined criteria.